The present invention relates to electronics assemblies, and is primarily concerned with racked assemblies. Many such assemblies will be located in racks for housing in for example nineteen inch cabinets, or other size cabinets such as twenty three inch or metric cabinets. The assemblies may for instance be employed as servers for a number of systems, for example in local area networks (LANs), wide area networks (WANs), telecommunications systems or other operations such as database management or as internet servers.
Such an assembly will typically comprise a supporting chassis that houses a motherboard or backplane and a number of daughterboards or module cards that extend in planes generally perpendicular to the plane of the motherboard and which are connected to the motherboard by connectors, e.g. high density connectors, so that the daughterboards can simply be located on guides and pushed toward the motherboard in order to connect them to it. An assembly will typically have dimensions in the order of 0.5 m in each direction and will be located in an enclosure, for example a cabinet, in an office, data centre, computer room or similar environment. Often, more than one such assembly is located in the same enclosure, and will need to be accessed from time to time for routine maintenance, repair or upgrading.
Because of the amount of heat that is generated during operation of the equipment and the thermal sensitivity of the equipment, it is necessary to provide cooling fans in order to direct a current of air through the assembly or otherwise permanent damage would occur. Typically air blown through the assembly needs to be filtered to remove dust and other contaminants. Replacement of the filters generally leads to downtime of the system, the length of which should be minimised.
According to one aspect, the present invention provides an electronics assembly which comprises:
(i) a chassis;
(ii) at least one front panel that is arranged in front of the chassis to obscure the chassis; and
(iii) at least one device that is mounted on the chassis and supports the or a front panel,
wherein the or each device or the or each panel includes at least one retaining element that extends out of the device or panel and is received in a recess in the or each panel or in the or each device respectively to retain the panel on the chassis, the element being manually retractable into the device or panel to allow the panel to be removed from the chassis.
Such an assembly has the advantage that the panel can be removed and replaced within a very short period of time, often no more than a matter of seconds, thereby minimising the danger of contamination of the system.
The panel or panels may be located on the front surface of the chassis where this surface has the array of air filters. In such an assembly, the motherboard may be located horizontally at the bottom of the assembly and the daughterboards are arranged vertically above the motherboard. In order to cool the electronics components, an array of fans may be arranged in the front wall of the chassis to blow air through the chassis from the front to the rear.
The retaining elements may be located either on the device(s) or on the panel(s), but usually they will be located on the devices. In order to enable the service engineer to manipulate the retaining element as easily as possible, for example simply by using a finger, the retaining element may be biassed out of the device or panel by means of a spring, and also may be provided with a tab or other projection that extends from the side thereof to enable it to be retracted. The service engineer can then simply hold a panel with one hand and flick the retaining element with a finger of the other hand to release the panel from the chassis. Retaining elements will normally be provided at the top and bottom of each panel. It is not necessary for all the retaining elements to be retractable since it is possible, for example, for the upper retaining elements to be retracted to release the top part of the panel, and the panel then simply be lifted off the chassis. Alternatively, retaining elements may be retracted at the top and the bottom of the panel and the panel then be pulled away from the chassis.
A single panel only may be present if desired. However, it is often more convenient for more than one panel to be employed so that any panel obscures only part of the front of the chassis. For example, a pair of supporting devices may be provided, one on either side of the chassis, and each device supporting one of a pair of panels. This arrangement is particularly convenient when the electronics assembly is supported in an enclosure, for example a cabinet, by means of a telescopic slider mechanism. Such mechanisms usually comprise a pair of telescopic sliders, one arranged on either side of the chassis, each having a fixed part that is fixed with respect to the enclosure, and a movable part that is attached to the chassis, and the telescopic slider is extendable to allow the chassis to be pulled out of the enclosure and retractable to allow the chassis to be pushed back into the enclosure. In such a form of enclosure, the or at least one device may have an arrangement for enabling it to be secured to the fixed part of the slider mechanism or to any other part of the enclosure in order to prevent removal of the chassis from the enclosure. The telescopic sliders will normally be arranged on posts within the enclosure and will extend on either side of the chassis horizontally from the front to the rear thereof. The device, on the other hand, will normally extend vertically over the height of the chassis at the edge between the front of the chassis and the side, in order to provide support at both the top and the bottom of each panel. When the chassis is pushed into the enclosure, the front end of the fixed part of each telescopic slide will then be adjacent to the edge between the front and side faces of the chassis, and the fixed part of the telescopic slide may conveniently be secured to the device. Where more than one device is employed, each device may be attached to the front end of the telescopic slide. In certain circumstances, it may be appropriate for the securing arrangement to require the use of a tool in order to release the device from the slider mechanism or the enclosure in order to prevent accidental or unauthorised access to the electronics assembly. Such arrangement may, for instance, be in the form of a lock that requires key access, or in an alternative arrangement, it may simply require a screwdriver to release the chassis.
Where the chassis is designed to be pulled out of the enclosure, for example on telescopic slides, a handle may be provided on the or each device to enable the chassis to be grasped easily. Such a handle may simply be a lip having an arcuate transverse cross-section along at least part of its length.
The electronics assembly will need to be pulled out of the enclosure for access to the interior thereof for maintenance, repair or upgrading. However, if access to the assembly is required merely to change the air filters in the front panel, which may well occur at more frequent intervals, it may not be appropriate to require the assembly to be removed from the enclosure, and so the assembly may be designed to allow removal of the panel(s) when it is still located within the enclosure.
The panels may be designed simply to be fixed to the front surface of the chassis and lifted off the chassis sip when necessary, for example to change air filters. However, the assembly may be provided with other equipment that requires access. For example, in one form of assembly, a panel having displayed information may be present, or equipment such as disc drives, tape drives and the like may be located on the front surface of the chassis. Such equipment may still need a through flow of air for cooling, and hence will need air filtering, but without the need to remove the panel for access. In such a case, the retaining elements may be in the form of pins or other retaining devices having a circular cross-section that are received in circular holes in order to enable the panel to be swung open in the manner of a door.
According to another aspect, the present invention provides a chassis for an electronics assembly which includes at least one device that is mounted on the chassis for supporting a panel in front of the chassis to obscure it, wherein the or each device includes at least one retaining element that extends out of the device and can be received in a recess in the or each panel for retaining the panel on the chassis, the element being manually retractable into the device to allow the panel to be supported by, or removed from, the chassis.
The device for supporting the panel is novel per se and so, according to another aspect, the invention provides a device for supporting a panel on the chassis of an electronics assembly, the device comprising an elongate body that is mountable on the chassis and has, at each end thereof, a retaining element that extends out of the device to be received in a corresponding recess of a panel and which is manually retractable into the device in order to release the panel.
There will usually be relatively little room between the chassis and the walls of the enclosure, so that the body of the device will be relatively narrow having a width in the region of about 2 to about 3 cm. It may, for example, be in the form of an elongate moulding having a generally flat portion that is securable to a side surface of the chassis at the front thereof, and a flange extending along substantially the length thereof that will lie in a plane parallel to the plane of the front surface of the chassis and extend between the chassis and the side wall of the enclosure to obscure the end of the telescopic slider mechanism. With such a form, when the chassis is pushed back into the enclosure, a part of the flange will abut the front end of the slider mechanism, and this part of the flange may be provided with an arrangement for securing it to the slider mechanism.